Poor posture during prolonged sitting activities has been identified as the root problem of the growing number of back, neck, extremity pain, and repetitive strain injuries being reported.
Back support devices for cushioning and supporting the user's back while the user is seated are well known. For example, a back support device is described in U.S. Pat. No. 5,403,067 to Rajaratnam. The back support device described by Rajaratnam cushions and cradles a user's back, deforming to adopt the shape of the user's back and to provide lateral pressure.
A significant drawback of the Rajaratnam device is that it does not correct or modify the user's poor sitting posture, but rather the device allows the user to assume his or her sitting posture and the device then molds to the user. Many users will adopt a poor posture, especially when seated, causing the spine to misalign, which exacerbates any back or neck pain. Accordingly, such devices are prone to misuse and fail to adequately address the issue of poor sitting posture.
Another shortcoming of devices like that described by Rajaratnam is that when it is placed in a chair its lower thickness effectively shortens the depth of the seat of the chair, thereby causing the user to sit too far forward on the seat. In some devices, this will also result in a user leaning too far backwards in the chair in order to bring his or her upper back into contact with the upper part of the chair. Most chairs are reasonably well designed to provide adequate leg and upper back support, and are sized to have an appropriate seat area. Where most chairs fail to provide adequate proper support is in the lumbar region.
When considering proper posture, it is important to note that proper posture is unique to an individual. The correct fit of an ergonomic device for one user's posture will not be the correct fit for another.